(1) Field of Art of the Invention
This invention relates to a method and apparatus for automatically maintaining a boat at or very near a speed set by the operator.
(2) Description of the Related Art
Devices for manually adjusting the speed of a boat by moving the throttle valve or other speed regulating device of the boat engine are well known. These devices are not, however, automatic control systems which continuously monitor the boat speed and hold it constant, and therefore these devices allow the speed of the boat to drift under the influence of disturbances from a water skier, or other outside sources such as changing wind and waves. While certain automatic control systems are commonly employed in automobiles and other similar land vehicles, they are not suited for use in boats. Devices which automatically adjust the speed of boat engines for the purpose of synchronization of the speed of two or more engines are well known, but do not function to control the speed of the boat, but rather the relative rotational speed of two or more engines (see, for instance U.S. Pat. Nos. 3,986,363, 4,586,341, and 4,741,165).